Internal combustion engine

ABSTRACT

A transfer postless two-stroke cycle internal combustion engine that has a stepped tube-like piston that cooperates with a cylinder head of related form to provide better scavenging and more horse power relative to present engines.

[451 Jul 31,1973

United States Patent [m Cseh 1,562,735 11/1925 Bongiovanni...................... 123/65 S l INTERNAL COMBUSTION ENGINE Inventor: Fennc Cseh 37 Passaic Passaic, ,354,667 10/1920 Lawler............................... 123/65 S Primary Examiner-Martin P. Schwadron [22] filed: '1 Assistant Examiner-A. M. Zipcic [57] ABSTRACT A transfer postless two-stroke cycle internal combus- 123/65 S F02d 39 04 [58] Field of 123/6 5 5 engine that has a StePPed Pism" operates with a cylinder head of related form to provide better scavenging and more horse power relative to present engines.

[52] US. [51] Int.

[56] References Cited UNITED STATES PATENTS 1,076,877 10/1913 7 123/65 S 2 Claims, 1 Drawing Figure PATENTED JUL 3 1 I975 INVENTOR:

FERE/VC OSEH llllll INTERNAL COMBUSTION ENGINE THE DISCLOSURE This invention relates to the art of internal combustion engines and more particularly to an internal combustion engine having a two-stroke cycle and high performance.

The object of this invention is to provide a novel two- 2 stroke cycle internal combustion engine within the family of the stepped tube piston type engines. In these engines the admission of transferring charge occured at the upper end of the cylinder, through transfer ports. The ports are opened by the coaction of the upper end of piston with the upper end of cylinder at lower piston position. In view of performance, these engines of the past despite having much promising construction and operation, couldnot full fill the expectation. A common blocking feature is the wall section between transfer ports, create a bottle neck and an obstacle to the flow of transfering fuel-air mixture, prevent a high speed operation of the engine. Furthermore, behind the said wall section are projected areas where insufficient purge takes place, unwanted turbulence-setsin, namely mixing the fresh with burnt gases. Low torque and bad economy is the result. The object of this invention is to remedy the afore-mentioned shortcomings by the introduction of a transfer gap as means to admit thetransferring charge into the cylinder. The transfer gap necessitate the employment of an open ended, stepped tube piston which with its novel shorter transfer conduit form a transfer gap to the closed upper end of the cylinder at lower piston position. The upper smaller diameter tube portion of piston termed transfer conduit. The freed, undivided flow of fuel-air mixture through transfer gap provide turbulence free, effective scavenging, conducive to higher torque and better economy. The transfer gap provide larger admission area for the transferring charge, conducive to higher maximum revolution per minute in operation. The higher torque and higher maximum revolution per minute means more specific horse power output, namely more horse power per cubic inch of piston displacement output. The excellent cooling effect on piston, even improves with increasing revolution per minute, permits closer fitting of piston into the cylinder and annular cavity hereby greatly reduces the engineering task of seals. The cooler piston permits lighter construction of it, condu cive to smoother engine operation. Other objects and advantages of this invention can be seen as this specification proceeds. Production of an internal combustion engine having the above advantages accordingly becomes the principal object of the invention. The intended application of this engine is primarily at the areas where high specific power output required, to name one: Meter cycle engine.

This invention will be explained in conjunction with the accompanying drawing which is a fragmentary elevational view partially in section of aninternal combustion engine incorporatingthe teachings of this invention. It is to be. understood that certain conventional details of construction which do not pertain to the invention per so have been eliminated for the sake of clarity.

Referring to the drawing, the numeral designates generally a cylinder which may be. one of several provided in an internal combustionengine. In accordance with conventional practice, the cylinder 10 communicates with a crankcase 11 which houses a crank shaft 12 in bearings not shown. The crank shaft 12 is pivotally connected, again in conventional fashion, to a piston rod 13 which is pivotally connected to a unique stepped tube-like piston 14 through a wrist pin 15. Thus, the reciprocation of slidingly and sealingly mounted piston 14 provides the usual rotary motion of crank shaft 12. The cylinder 10 at the upper end is covered with cylinder head 17 equipped with spark plug 16. The cylinder head 17 incorporates a deflector l8 and a sea] 19. The deflector l8 incorporates annular cavity 9. At the bottom portion of cylinder head 17 is the annular shape combustion chamber. The cylinder 10 is equipped with spaced intake port 21, controlled by the lower edge of piston 14. The cylinder 10 is equipped with spaced exhaust port 22, controlled by the top edge of piston 14. The piston 14 is further characterized by having a lower edge which fully opens intake port 21 when said piston is in top dead center position, furthermore having a ring shape top surface at the step portion of said piston and having a top edge which fully opens the exhaust port 22 when said piston is in bottom dead center position. The top of said piston extends into a transfer conduit or passage which with its upper end, in conjunction with the inner edge of said combustion chamber, fonns the transfer gap 23 which is fully open when said piston is in bottom dead center position. The combustion chamberdefined as the left volume over the top of piston when the said piston is in top dead center position.

It is believed that the invention will be. more clearly understood from a consideration of the operation of the apparatus just described, and such a description follows herewith.

OPERATION As seen on the drawings, piston 14 is at the bottom dead center position. In this position the scavenging process takes place. The trapped and primarily compressed fuel-air mixture, located in the crankcase chamber more precisely in the crankcase 11 and some lower portion of cylinder l0 and the hollow of piston 14, passes through transfer gap 23 with high speed, e'xpulsing the remains of exhaust gases, located in the expansion chamber, through exhaust port 22. As crank shaft restates, the piston 14 moves upward and closes the transfer gap 23, cutting off the flow of fuel-air mixture. With the same action the crankcase chamber cut off from atmospheric pressure and further rise of piston 14 will decrease the pressure in it. Further rotation of crank shaft 12 will move piston 14 to upper position closing off exhaust port 22 with the top edge of piston 14, trapping the charge. The further rise of piston 14 will secondly compress the trapped fuel-air mixture above the top of piston 14 meanwhile creating depression in the crankcase chamber till the lower edge of pis-' ton 14 reaches the lower edge of intake port 21 and opens it. The pressure difference will make the fresh fuel-air mixture to flow into the crankcase chamber. As piston 14 moves upward to top dead center position the trapped and secondly compressed fuel-air mixture above the top of piston 14 ignited by spark plug 16, and combustion takes place. The burnt high pressure gases force the piston 14 move downward, rotating crank shaft 12. As piston 14 moves downward, the lower edge of piston 14 reaches the lower edge of intake port 21' and traps the fuel-air mixture in crankcase chamber.

The trapped fuel-air mixture gets primarily compressed as piston 14 moves further downward during power stroke. When the top edge of piston 14 reaches the upper edge of exhaust port 22 and opens it, the burnt and expanded gases get exposed to atmospheric pressure hereby a sudden pressure decrease takes place in the expansion chamber. Further downward movement of piston 14 will open transfer gap 23 by the upper end of transfer conduit getting under the inner edge of combustion chamber. The primarily compressed fuel-air mixture of crankcase chamber rush through transfer gap 23, expelling exhaust gases through exhaust port While in the foregoing specification a detailed description of the invention has been given for the sake of clearly teaching the invention, it is to be understood that the invention is not intended to be limited to the specific embodiment herein shown. It will be readily apparent to those skilled in the art that many variation in the details thereof may be made without departing from the spirit and scope of the invention.

I claim:

1. A two-stroke cycle internal combustion engine comprising:

a. at least one cylinder having an axially spaced exhaust port formed in the wall thereof;

b. a cyclinder head having a bore therein;

c. a deflector received in said bore and having an annular chamber formed therein which chamber is in communication with said cylinder;

d. a stepped piston received within said cylinder having upper and lower portions, said upper portion dimensioned to fit into said annular chamber, said lower portion dimensioned to contact the wall of said cylinder;

e. a transfer passage formed longitudinally through said stepped piston;

and means mounting said stepped piston for reciprocal motion between a top dead center position in which said upper portion extends into said annular chamber and a bottom dead center position in which said upper portion is axially spaced from said deflector and its associated annular chamber forming a transfer gap, said means permitting inlet gases to pass through said transfer passage when said upper portion is axially spaced from said deflector to aid in expelling said exhaust gases through said exhaust port.

2. In a two-stroke cycle internal combustion engine having at least one cylinder with an exhaust port formed in the wall thereof, a cylinder head, a deflector within said cylinder head and having an annular chamber therein in communication with said cylinder, a stepped piston within said cylinder having upper and lower portions, said upper portion dimensioned to fit into said annular chamber, said lower portion dimensioned to contact said wall and exhaust port, a transfer passage formed longitudinally through said stepped piston wherein the improvement comprises means mounting said stepped piston for reciprocal motion between a top dead center position in which said upper portion extends into said annular chamber and a bottom dead center position in which said upper portion is axially spaced from said deflector and its associated annular chamberv 

1. A two-stroke cycle internal combustion engine comprising: a. at least one cylinder having an axially spaced exhaust port formed in the wall thereof; b. a cyclinder head having a bore therein; c. a deflector received in said bore and having an annular chamber formed therein which chamber is in communication with said cylinder; d. a stepped piston received within said cylinder having upper and lower portions, said upper portion dimensioned to fit into said annular chamber, said lower portion dimensioned to contact the wall of said cylinder; e. a transfer passage formed longitudinally through said stepped piston; f. and means mounting said stepped piston for reciprocal motion between a top dead center position in which said upper portion extends into said annular chamber and a bottom dead center position in which said upper portion is axially spaced from said deflector and its associated annular chamber forming a transfer gap, said means permitting inlet gases to pass through said transfer passage when said upper portion is axially spaced from said deflector to aid in expelling said exhaust gases through said exhaust port.
 2. In a two-stroke cycle internal combustion engine having at least one cylinder with an exhaust port formed in the wall thereof, a cylinder head, a deflector within said cylinder head and having an annular chamber therein in communication with said cylinder, a stepped piston within said cylinder having upper and lower portions, said upper portion dimensioned to fit into said annular chamber, said lower portion dimensioned to contact said wall and exhaust port, a transfer passage formed longitudinally through said stepped piston wherein the improvement comprises means mounting said stepped piston for reciprocal motion between a top dead center position in which said upper portion extends into said annular chamber and a bottom dead center position in which said upper portion is axially spaced from said deflector and its associated annular chamber. 